I don't know if we have a common thread here with your John Walker Thompson and my J.W. Thompson that I'm looking for.

However this is what I have ;
J.W. Thompson son of Lennox and Mary Thompson of Simcoe, Ontario. I believe he was born early to mid 1800's in the Simcoe area. In old family letter's they note J.W. Thompson was a business man.
I know that Lennox and Mary had thirteen children, but I do not know all there children's given names, and dates of birth.
If any of this sounds familiar, I look forward to hearing from you.

Richard J. Thompson